Container with flexible reinforced wall members

ABSTRACT

A relatively flexible container comprising a bottom wall and sidewalls extending upwardly therefrom. The bottom wall contains rib means which provide for the downward bulging of the bottom wall when opposing sidewalls of the container are pressed inwardly.

United States Patent Inventors Roy W. Bloch Northbrook;

Donald K. Jewell, Chicago, lll. 828,542

May 28, 1969 May 1 l, 197 l Ekco Products, Inc.

Wheeling, Ill.

Appl. No. Filed Patented Assignee CONTAINER WITH FLEXIBLE REINFORCED WALL MEMBERS 6 Claims, 3 Drawing Figs.

U.S. Cl 220/72, 229/25, 150/.5

Int. Cl. B65d 7/42 Field of Search 220/72, 66,

43 (P), 60 (A); 229/25; ISO/.5; 206/46 (Food) [56] References Cited UNITED STATES PATENTS 3,098,597 7/ 1963 Johnson et al. ...f 229/25 3,104,776 9/ 1963 Bostrom 220/72 3,151,799 1011964 Engles, Jr. et al 229/25 FOREIGN PATENTS 442,634 4/1927 Germany 220/ 60A 6,609,61 l l/ l 968 Netherlands 220/43P Primary Examiner--Raphael H. Schwartz Attomeys-Robert D. Teichen and Donald J. Koprowsk ABSTRACT: A relatively flexible container comprising a bottom wall and sidewalls extending upwardly therefrom, The bottom wall contains rib means which provide for the downward bulging of the bottom wall when opposing sidewal of the container are pressed inwardly. v

Il. .l

nl i f lill Inventor Donald K.Je ell Homey Roy-W. Bloch I 1 CONTAINER WITH FLEXIBLE REINFORCED WALL MEMBERS BACKGROUN D OF THE INVENTION Y Flexible containers, especially those constructed of thermoplastic material, generally are becoming more and more useful in the packaging field, primarily in the packaging of foods. One of the more recent developments in this field has been the concept of providing disposable containers for serving food in large institutions such as schools and hospitals. A typical example of this type of system is where the food is prepared in central kitchens, packed in the disposable containers, and then distributed to satellite institutions for serving. After the food has been consumed thecontainers are easily disposed of, thereby eliminating the need for kitchen facilities in the satellite institution and the need for dishwashing labor and equipment.

A typical meal package may include a main course, such as meat and potatoes, and side dishes, such as slaws, salads, fruits and desserts. The side dishes would normally be packaged in smaller containers, such as souffle cups, within the larger,

overall containers. f ln order to save on material, it is advantageous to make the containers in which this food is served as thin as possible. Normally, however, when the container is made very thin it becomes very susceptible to damage in handlingfln particular,

when a container is grasped at opposing sidewalls and pressed inwardly, the thin bottom wall of the container will distort in a random fashion. Usually, at least a part of the bottom wall of the container will bulge, kink, or snap upwardly, thereby causing the contents, such as the side-dish souffle cups, to be thrust upwardly. If the container is not covered, part of the contents may be ejected therefrom; if the container is covered with an overwrap, the contents may be thrust upwardly against the overwrap and will stick thereto and thereby cause a messy condition which is, ofcourse, undesirable. When the overwrap is removed, part of the contents of the container would remain v thereon.

Accordingly, it is an object of this invention to provide a container in which the bottom wall will buckle downwardly when opposing sidewalls are pressed inwardly thereby preventing the disadvantages described above and providing for neater, more efficient handling of the container.

Other objects and advantages `of the invention will be pointed out specifically or will become apparent from the following description when it is considered in conjunction with the appended claims and the accompanying drawings.

SUMMARY OF THE INVENTION container or from being ejected therefrom. Though the invention may be applied to containers made of other materials, it will hereinafter be described in terms of a container constructed of thermoplastic material such as polystyrene, polyethylene, P.V.C. or polypropylene.

DESCRIPTION OF THE DRAWINGS 2 DESCRIPTION OF THE PREFERRED EMBODIMENTS As a preferred or exemplary embodiment of the present invention the drawings illustrate the substantially rectangular container l0 constructed preferably of a relatively flexible thermoplastic material. Satisfactory containers have been produced from material having thicknesses in the range of 5 to l l mils. The container comprises a bottom wall l2 and sidewalls I4 exter-.ling upwardly and outwardly therefrom. The sidewalls 14 preferably contain corrugations 16 which increase their strength. The sidewalls 14 terminate preferably in a peripheral rim 18. To impart strength to the rim 18, a step 20 may be provided therein. The comers 22 of the sidewalls are preferably rounded as are the junctions 24 between the sidewalls 14 and bottom wall l2. After the container l0 is filled with its intended contents, it will usually be covered with an overwrap of suitable material (not shown).

To ensure that the bottom wall l2 of the flexible container l0 will bulge downwardly` when the container is grasped at opposing sidewalls 14 and pressed inwardly, the bottom wall 12 is provided with ribs indicated generally by the numeral 26. The preferred embodiment in FIG. l shows a substantially circular rib 26a and transverse ribs 26h including curved segments substantially concentric to the circular rib 26a. A peripheral rib 26C surroundsthe transverse ribs 26h and circular rib 26a. The ribs are preferably concave downwardly as shown in FIG. 3.

In practice, the container will be handled several times before its final use and disposal. It will rnost conveniently be grasped at opposing sides 14 and pressed inwardly, usually along the short dimension. When this is done, the peripheral rib 26C acts as a hingelike member or pivot point, the sidewalls 14 and bottom wall I2 will rotate about the rib 26C forming an acute angle between the sidewalls I4 and bottom wall I2 at the locations at' which the container is grasped. The bottom wall l2 then becomes offset slightly downwardly and any increase in pressure on the sidewalls 14 will cause the bottom wall l2 to bulge downwardly still further. The downward motion of the bottom wall is accommodated also by the curvilinear configuration of the substantially circular rib 26a and the traverse ribs 261;. lmparting strength along their lengths, they tend to disperse the forces applied at the sidewalls 14 in a manner that urges the bottom wall l2 into its downwardly bulged position as shown by the dotted line in FIG. 2. Thus, it is apparent that the invention overcomes the disadvantages, and fulfills and meets the objectives and advantages hereinabove described.

None of the ribs 26a, 26h and 26e need necessarily be continuous as shown in this preferred embodiment. Also, other configurations of ribs in the bottom wall may be used. 1

Thus, while a preferred embodiment of the invention has been illustrated herein, it is to be understood that changes and variations may be made in the form, construction, and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form-hereinbefore described being merely a FIG. l is a top plan view of a preferred embodiment of the 2 l present invention.

FIG. 2 is an end elevational view showing the container both in a normal condition and with its walls in a deflectedposition when opposing sidewalls are pressed inwardly.

FIG. 3 is an enlarged fragmentary sectional view taken substantially along line 3-3 of FIG. l.

preferred embodiment thereof.

We claim:

l. A relatively flexible container comprising a bottom wall and sidewalls extending upwardly and outwardly therefrom, said bottom wall having rib means to provide for the downward bulging of said bottom wall when opposing sidewalls of said container are pressed inwardly, said rib means comprises a peripheral rib disposed inwardly from said sidewalls and a plurality of curvilinear transverse ribs extending across the area of said bottom wall defined by said peripheral rib,

2. The container set forth in claim I wherein said sidewalls have substantially vertical corrugations formed therein.

3. The container set forth in claim 2 wherein said corrugations extend into at least a portion of said bottom wall, said corrugations terminating outwardly of said peripheral rib.

4. The container set forth in claim 2 including a substantially circular rib substantially centered in said bottom wall.

5. The container set forth in claim 4 including a substantially circular rib centered in said bottom wall. 

1. A relatively flexible container comprising a bottom wall aNd sidewalls extending upwardly and outwardly therefrom, said bottom wall having rib means to provide for the downward bulging of said bottom wall when opposing sidewalls of said container are pressed inwardly, said rib means comprises a peripheral rib disposed inwardly from said sidewalls and a plurality of curvilinear transverse ribs extending across the area of said bottom wall defined by said peripheral rib.
 2. The container set forth in claim 1 wherein said sidewalls have substantially vertical corrugations formed therein.
 3. The container set forth in claim 2 wherein said corrugations extend into at least a portion of said bottom wall, said corrugations terminating outwardly of said peripheral rib.
 4. The container set forth in claim 2 including a substantially circular rib substantially centered in said bottom wall.
 5. The container set forth in claim 4 including a substantially circular rib centered in said bottom wall.
 6. The container set forth in claim 5 wherein said curved portions of said curvilinear transverse ribs are substantially concentric to said substantially circular rib. 